Well that's not pretty.

I'm assuming that the internet itself isn't doing that, right? Just PingPlotter? We've seen this pattern before - but it was the router actually rebooting itself (which obviously stops the internet from working during the reboot process).

There are a couple of things you can check:

* Are you running the latest bios for your router?
* Can you use the TCP packet type instead of ICMP?
* Does setting the trace interval at 15 seconds solve it? If so, how low can you get that number?

It looks like maybe there's a limit to how many packets the router allows in a specific time period (1 minute, based on your graph) - or maybe there *might* be some rule in the router that's kicking in and blocking traffic for a minute. Dig around and see if you can find anything related to ICMP.

- Pete